def foo():
    
  #ERROR: match
  f = o.foo().m().h().bar().z()

  #ERROR: match
  f = o.foo().bar()

  # this one does not contain the bar()
  f = o.foo().m().h().z()

  #ERROR: match $O can match o.before()
  f = o.before().foo().m().h().bar().z()
